Shell-stitch machine



Feb. 9 1926.

2 Sheets-Sheet 1 [raven/tar:

.Mijllermw 11118 Attorneys.

cfasepk y M Feb. 9 1926.

J. M. MERROW SHELL STITCH MACHINE Filed Jan. 23, 1923 2 Sheets-Sheet 2 15W mentor: iJoseplp MMC'I'I'OM/ By C 4 His Atorrpuys.

Patented Feb. 9 1926.

UNITED STATES PATENT OFFICE.

JOSEPH M. MERROW, OF HARTFORD, CONNECTICUT, ASSIGNOR TO THE MERROW' MACHINE COMPANY, OF HARTFORD, C NNECTICUT, A CORPORATION OF CON- NECTICUT.

SHELL-STITCH MACHINE.

Application filed January 23, 1923. Serial No. 614,373.

To alZ whom may concerted Be it known that I, Josnrn M. Meimow, a citizen of the United States, residing in the city of Hartford, county of Hartford, State of Connecticut, have invented certain new and useful Improvements in Shell- Stitch Machines; and I do declare the fol-' lowing to he a full, clear, and exact de sernption of the same, reference being had to theaccompanying drawings, forming a part of this specification, and to the characters of reference marked thereon.

This invention relates to oversea-ming machines and more particularly to machines for formil'ig shell stitch edging or border lllllSll'. on certain classes of work it is deenable to make the shells or clusters which i'aliaracterize such finish very small and to apply them to an accurately trimmed edge of material. Therefore, in connection with new varieties of shell stitch adapted for production in diminutive shells, my present invention has been developed and embodied in a machine of the Morrow overseaming type provided with trimming mechanism and stitch forming instrumentalities including loopers in lieu of the latch needle which is commonly employed in shell stitch nia-. chines. The trimming mechanism operating in advance of the stitching elements and simultaneously therewith prepares an even edge of material to receive the shell finish, and the latter by means of a suitable exchange of loopers may be made with either two or three threads. The arrangement "shown in the drawings is for producing the three thread finish.

1n the drawings,

Figure 1, is an end view of an overseaming machine of the Merrow type embodying my invention.

Figure 2, is a view similar to Fig. 1, but showing only the lower part of the machine with certain parts removed and others in section.

Figure 8, is a sectional view on line 33 of Fig. 1.

Figure l, is a sectional View on line l4.- of Fig. 1,-and

Figure 5, is a sectional view on line 55 of Fig. 1.

Like characters of reference designate like Parts mrsliqu the several views of :the drawings.

will be sufiicient to convey a clear understanding of the association therewith of the elements of the present invention. The stitching instrumentalities comprise curved eye-pointed needle 1, upper looper 2, and lower looper The needle receives its motion through the link 4:, which connects the needle carrier 5, with an eccentric projection or stud G, at the end of shaft 7. By mechanism (not shown) associated with upper shaft 7 and lower shaft 8, looper 2, is actuated to reciprocate and oscillate so that it passes in a curved path extending above and below the needle plate 9, arouirl one edge thereof, and looper 3, is reciprocated below the needle plate. The needle moves to cooperate with the lower looper belowthe needle plate and with the upper looper above the needle plate and the loopers below the plane of the needle plate move to cooperate with each other in a well known manner to form ovcredge stitching. The upper looper may be throated in form to engage a loop of thread from the lower looper, or it may be provided with an eye, asshown, to carry a thread of its own. "The throated form of looper, sometimes called a spreader, serves to carry a loop of the lower looper thread into a position above the ma-' terial to be entered by the needle and the eye form of looper serves to carry a loop of its own thread through a loop of the lower looper thread and into a position above the material to be entered by the needle. The variety of finish produced when the throated form of looper is used is composed of two threads while that produced by the other form of looper is composed of three threads, in either case, in the resulting finish, each thread engaging loop of each thread, extends through but one loop of another thread, and this peculiarity marks a distinguishing difference between the-new varieties of shells made by the ma chine embodying the present invention and the" shells made by machines using a latch needle instead of loopers.

-The tensions, take-ups and thread guides ne not be described in dct f Parts of trinnning mechanism such as commonly employed in the type, of machine illustrated, are shown in Figs. 1, 2 and l. Such mechanism, which is actuated in a well known manner, includes the lower cutter. 10, and upper cutter '11, which cutters cooperate to cut oil or trim .the edge of the work adjacentto one side of the needle plate, slightly in advance of the needle. 'lloth cutters are adjustable inthe usual manner, so that theline of trimming, or distance of the cutters from the line ofneedle penetration, may be-va ied.

l eed niecha s n for advancing the \SfOi'i at intervals of several cycles of the stitch torming instru nentalities and especially cinistr-ucted for practical association and cooperation with mechanism of-the type of machine illustrated will now be described. The l'eed dog actuating mecha-' nism employed includes a pivoted carrier wherein the feed. dog is inountedior:reciprocatory movement. hlovement pivotally of the carrier,intermittently causesan engagement of thefeed dog withthe worlr during movementof the feed dog effective for advancing the work, and .as will hereinafter more fully appear, the reciprocations of the feed dogiare synchronizedwi'th the stitch forming cycles so.th at the movement for advancing the ,;work can occur only while the needle-is disengaged therefrom, and it will also appear that engagement of the feed dog with-the work occurs only at intervals of several .stitchforining cycles sothat the needle will penetrate the work repeatedly subs tantially .-at the same point thereby producing a shellor cluster ot' stitches.

The .feed dog 14., is provided with a shank vl5, for sliding association with a suitable carrier '1:.G,lthe latter being channeled at 17, to receive thefeed dog shank and pivoted .at18,. to a bracketlQ, which also supports the work plate 2.0. Lateral support is providcdiorthezteed dog carrier by .side wallscof. the slot 21, in which it. is pivoted and also by. contact with theblock 22, (see Figs.2 andJB) secured-as byscrews at the end ofethe .machine .-irame 24. The feeddog 1.4, isalso'laterallyisupponted by the blockilfZ, and maintained. .ther eby in its guiding chamiel l7, inhcarnierlo.

lalechanisni 51- actuatmgzthe feedsdog and that tor actuating ltsocarrier' 1s lasso:-

ci ated =with; the main shaft :8, beneath 1 the work plate and is enclosed in w-a housing formed. by the lower cutter vsupport[25, the /iiang d "be t ng 19 .216, egql- 191191 rfoot mechanism, therefore these parts plates 27 and 28, which are secured to said bearing bloclnicover plate 28, being held by the knurled screw 29, and extended into 'Means for reciprocating the feed dog and adapted through a sliding pivotal connection to permit the movement imparted thereto by'its carrier, include a lever arm 3-1, having a hub 32, pivotally supported on a stud shaft 33, which extends through the bearing block, 26. 'At its free end, lever arm 31, is forked to engage a flanged block 34, which is pivotally carried by a pin 35, rigid with thefeed dog and extending through an aperture 36, in the feed dog carrier, The required movement of ,lev r 31, is derived from an eccentric 37, on shaft 8, and transmitted through link 38, and stud 39, the latter being enlarged at Al between the lever and link to form a shoulder for maintaining the link in alignment with, its eccentric. The length oi. strokeimparted :to the feed dog is con trolled by adjusting stud 39, in slot 41, of lever '31, the slot engaging part ,-l2, of the stud which is flattened to prevent its turning, being extended and threaded at 4.3, to receivennt 44;. It will'be noted that slot in lever 31, is ofarcuate form and so related to the eccentric 37, that adjustment of? stud 39, in said slotwillnot materially alter the position ,of the feed .dog at the forward end ofitsrange of movement,,the variation in the stroke occuring at the, other end. thereof. i

From thezforegoing it will .be clearthat the feedldog is reciprocated. .once for each reciprocation of the needle, that is to say, once for each cycle of the stitch forming implements It follows that in producing a shell composed of several stitches secured atpracticallythe same point, the feed dog usteflect advance of the Work only at intervals of several stitch forming cycles. Tins-result as beforeintimated is accomplished by moving the feed dog carrier in a manner to cause the feed dog to engage the work once 01 each several:reciprocations thereof. Suitable means forlhus moving the feed dog carrier include an element 15, mounted for rotation on shaft ll which is supported -byqbear-ing block-2? In its lateral face,and adjacent theiecd dog carrier, element 45, v is provided with (ra n groove .l'l yllO receive camroll d8, which supported on stud 4.9, slotted at 50, for a purpose that will hereinafter appear. The stud 49 is extended at its rear end in the form of aneccentr-ic shank 52, adapted to be adjustably held in a depending part of the-feed dog carrier; by screw The-cam groove 47, by virtue ot the described relation of parts between it and the -feed- 'clog,

determines the position of the feed dog vertically with respect to the work plate. For each revolution 01 the cam, the feed dog is moved into position to engage the work, and

.in order that this action may occur at desired intervals, the cam element 45, is provided with gear teeth which mesh with the pinion 56, formed at the end of shaft 8. The driving; relation between this pinion ant, gear may be in any suitable ratio, that illustrated is live to one, in which case the feed dog engages the work to advance it after each five cycles of the stitch forming implen'ients, thereby forming a shell stitch edge composed of shells of live stitches each. The amount the feed dog teeth are projected above the work plate may be regulated within suitable limits by adjusting; the eccentric stud 4,9, which, with the screw 5%, loosened, may be turned by a screwdriver introduced throug h holes 58 and 59, respectively in the flange of bearing block 26, and the cam and gear element is.

It will be seen that the trimming mecha nism must embody cutting edges which will, during; the time the work is practically stationary, cut a length of the edge which is as great or slightly greater than the length of the long feed which occurs be twen successive clusters of stitches, and in this connection it will be noted that the feed dogs should always start their work feeding movement at practically the same time with relation to the trin'nner operation, and stitch forming operation regardless oi the distance between groups of itches, such desirable result being accomplished by the shape or curvature of the slot 4:1.

Having thus described my invention, what I claim is,

1. In a shell stitch overedging machine comprising stitch-forming mechanism and feeding mechanism associated to form clusters of stitches at successive spaced points on the work, the combination of trimming mechanism comprising cutters operating in consonance with the stitch-forming and feeding mechanisms, located adjacent the feeding and in advance of the stitch iornr mechanism, said trimming mechanism havin cutt-ing edges of a length 110 less than the c: tance between clusters of stitches formed by the stitch-forming and feeding mechanisms.

2. In a shell stitch overedging machine comprising stitch forming mechanism and.

feeding mechanism associated to form clusters of stitches at successive spaced points on the work, the combination of trimming n'iechanism comprising cutters operating in consonance with the stitch forming and feeding mechanisms, said cutters having cutting edges of a length no less than'the greatest distance between clusters of eluding; a feed dog, means 101' actuatino' the feed dog to advance the work at intervals of several cycles of the stitch forming elements to form clusters of stitches, and trimming mechanism in advance of the stitching elements having cutting ed 'cs of 89 a length equal to or greater than the distance between clusters of stitches.

4. In an overedge sewim machine in eombination with a support I01 work, feeding mechanism including a reciprocatwy feed dog, a carrier in which the feed dog is mounted to reciprocate and itself mounted to oscillate about a fixed axis, means for reciprocating the feed dog in its carrier,

means including gear provided with a 90 cam groove for oscillating the feed dog carrier to position the feed dog above the work support, a stud having an eccentric shank for associating the feed dog carrier with the cam groove and means for permitting adjustment of the stud to vary the amount of projection of the feed dog above the work support.

5. In an overcdg e sewing machine, lieeding mechanism including a feed dog, a car rier in which the feed dog is mounted to reciprocate and itself mounted to oscillate about a fixed center, means for reciprocatingi; the feed dog in its carrier including, an eccentric and lever disposed on opposite sidesof the carrier, a link associated with the eccentric and a stud for connecting the link with the lever, the latter being provided with an arcuate slot to permit adjustment of the stud therein to thereby vary at one, 0

end the length of stroke imparted to the feed dog.

6. In an overedge sewing machine, feed" ing mechanism including a feed dog, a movable carrier in which the food dog is mounted to reciprocate, means for reciprocating the feed dog including an eccentric and a lever located, respectively, on opposite sides of the carrier and contiguous thereto and a link pivot-ally connected with the lever and eccentric for transmitting motion from the eccentric to the lever:

7. In an overedge sewing machine, feed ing mechanism including a feed dog, a pivoted carrier in which the feed dog is mounted for reciprocation, and means for reciprocating the feed dog which include motion trans mitting elements contiguous to and affording guiding support on opposed sides of the carrier. 7

8. In an overedge sewing machine, the combination in feeding mechanism, of a feed dog, a pivoted carrier in which the feed dog is mounted for reciprocation,

neans including an eccentric for reciproeating the feed dog located on one side of the carrier and means including a gear for oscillating the feed dog carrier located on the other side of the carrier and an operat' ing shaft for the eccentric and gear extending beneath the carrier.

9. In an overedge sewing machine, the combination in feeding mechanism, of a feed dog, a pivoted carrier in which the feed dog is mounted for reciprocation, means for reciprocating the feed dog comprising a shaft, an eccentric onthe shaft, a link on the eccen trio, a pivoted lever, and suitable connections between the link and 'lever and the lever and feed dog, and means for oscillating the carrier comprising a pinion on the shaft, a cam grooved element having gear teeth in mesh with the pinion and suitable connections between the cam groove and the carrier, the eccentric and link being on one side and the pinion, gear element and lever on the other side of the carrier.

10. In an overedge sewing machine, feeding mechanism including in combination a shaft supported in a bearing of the machine frame and projecting therebeyond, an

eccentric on the shaft adjacent to the end of the machine frame a pinion at the end of the shaft, a feed dog carrier pivoted at one end for oscillation in a plane extending at right angles tothe axis of the shaft and lying between the eccentric and the pinion, a feed dog mounted for reciprocation on the feed dog carrier, a pivoted lever for recip-c rocating the feed dog, a gear in mesh with the pinion and having a cam groove, means on the feed dog carrier forengaging the cam groove and means for transmittingv mo tion from the eccentric to the lever,

In testimony whereof I have signed my name to this specification.

JOSEPH M. MERROVV. 

